This invention relates to a fuel injection device for injecting pressurized fuel into a combustion chamber of an internal combustion engine and, more particularly, to a fuel injection device for diesel engines, among internal combustion engines.
As the prior art fuel injection device of the type noted, fuel injection systems are disclosed in U.S. Pat. Nos. 4,378,774, 4,385,609 and Japanese Utility Model Disclosure (KOKAI) No. 59-96362. Any of these well-known known fuel injection systems have an electromagnetic valve for controlling the amount of fuel to be injected. The electromagnetic valve is provided in a fuel supply passage connecting an injection pump chamber and a feed pump for supplying fuel toward the injection pump chamber. The amount of fuel that is led to the injection pump chamber thus can be controlled by controlling the "on" period of the electromagnetic valve, during which the valve is open. In other words, the amount of fuel to be injected can be controlled through control of the operation of the electromagnetic valve according to the engine operation.
Although the prior art fuel injection devices can control the amount of fuel to be injected according to the engine operation, they don't easily control the fuel injection timing according to the engine operation. However, to further improve the engine performance it is necessary to control both of these factors. Therefore, there is a demand for a fuel injection device, which can control the fuel injection timing as well as the amount of fuel to be injected according to the engine operation with an electromagnetic valve.